Physical Sciences and Mathematics Commons^™

Real-World Performance Of Current Proactive Multi-Hop Mesh Protocols, M. Abolhasan, Brett Hagelstein, Jerry Chun-Ping Wang

Faculty of Informatics - Papers (Archive)

The proliferation of mesh or ad hoc network protocols has lead to a push for protocol standardisation. While there are a number of both open-source and proprietary mesh routing protocols being developed, there is only a small amount of literature available that shows relative strengths and weaknesses of different protocols. This paper investigates the performance of a number of available routing protocols using a real-world testbed. Three routing protocols - Optimised Link State Routing (OLSR), Better Approach To Mobile Ad hoc Network (B.A.T.M.A.N.) and BABEL - were chosen for this study. Our investigations focus on the multi-hopping performance and the …

Complex Adaptive Systems As A Model For Evaluating Organisational Change Caused By The Introduction Of Health Information Systems, Kieren Diment Mr, Ping Yu, K. Garrety

Faculty of Informatics - Papers (Archive)

This paper documents the preliminary development of a framework for evaluating organisational change processes during the implementation of an electronic nursing documentation system in residential aged care facilities. It starts with a brief outline of organisational change processes. This is followed by a more detailed exposition of the principles underlying complex adaptive systems (CAS) theory, where we explain how mathematical concepts can be used to illuminate qualitative research approaches. Finally we present some preliminary findings on the facilitators and barriers for the introduction of the electronic documentation system, explained with reference to the CAS theory, based on analysis of interviews …

Rejoinder, Peter Craigmile, Catherine Caldert, Hongfei Li, Rajib Paul, Noel Cressie

Faculty of Informatics - Papers (Archive)

We agree with Schmidt that it is essential that researchers from many diverse areas have access to affordable, but still trustworthy, software. In this research project, substantial effort went into preparing datasets. Much of the data came from different government agencies, with databases arranged in multiple formats, often including variables that were not immediately relevant to our scientific pursuits. In our work on this project, the use of SAS was essential to producing clean datasets.

Accounting For Uncertainty In Ecological Analysis: The Strengths And Limitations Of Hierarchical Statistical Modeling, Noel Cressie, Catherine Calder, James Clark, Jay Ver Hoef, Christopher Wikle

Faculty of Informatics - Papers (Archive)

Analyses of ecological data should account for the uncertainty in the process(es) that generated the data. However, accounting for these uncertainties is a difficult task, since ecology is known for its complexity. Measurement and/or process errors are often the only sources of uncertainty modeled when addressing complex ecological problems, yet analyses should also account for uncertainty in sampling design, in model specification, in parameters governing the specified model, and in initial and boundary conditions. Only then can we be confident in the scientific inferences and forecasts made from an analysis. Probability and statistics provide a framework that accounts for multiple …

Measuring End-Users' Opinions For Establishing A User-Centred Electronic Health Record (Ehr) System From The Perspective Of Nurses, Yung-Yu Su, Khin Than Win, John Fulcher, Herng-Chia Chiu

Faculty of Informatics - Papers (Archive)

Establishing an acceptable user-centred electronic health record (EHR) system is a challenging task for healthcare providers due to the need for such systems to meet the requirements of its user population. Concerned nurses are the main end-users of EHR systems. Based on knowledge of evidence-based management (EBM) and the issues (goals and methods) of Health Information Systems (HIS) evaluation, this research was performed in four regional teaching hospitals by adopting a quantitative approach research design to perform “goal-based evaluation” research. The results of Path Analysis indicated that 17 of 21 hypotheses were accepted in this study. In addition, the results …

Application Of Microsimulation To The Modelling Of Terrorist Attacks, Ian Piper, Daniel Keep, Tony Green, Ivy Zhang

Faculty of Informatics - Papers (Archive)

In this paper, a novel approach to behavioural modelling is presented with reference to biological infection spread in communities. Its potential application to various terrorist-related scenarios is discussed in relation to attack point simulation and interdiction simulation.

Explicit Connections Between Longitudinal Data Analysis And Kernel Machines, N D. Pearce, M. P. Wand

Faculty of Informatics - Papers (Archive)

Two areas of research - longitudinal data analysis and kernel machines - have large, but mostly distinct, literatures. This article shows explicitly that both fields have much in common with each other. In particular, many popular longitudinal data fitting procedures are special types of kernel machines. These connections have the potential to provide fruitful cross-fertilization between longitudinal data analytic and kernel machine methodology.

Semiparametric Regression During 2003-2007, David Ruppert, M. P. Wand, Raymond J. Carroll

Faculty of Informatics - Papers (Archive)

Semiparametric regression is a fusion between parametric regression and nonparametric regression that integrates low-rank penalized splines, mixed model and hierarchical Bayesian methodology - thus allowing more streamlined handling of longitudinal and spatial correlation. We review progress in the field over the five-year period between 2003 and 2007. We find semiparametric regression to be a vibrant field with substantial involvement and activity, continual enhancement and widespread application.

Diffusive Growth Of Fullerenes And Carbon Nanotubes, J E. Bunder, James M. Hill

Faculty of Informatics - Papers (Archive)

The video of a growing fullerene within a carbon nanotube, initiated by a tungsten catalyst, provides a dramatic realization of a complex nanoscale process. While there may be many detailed models which can account for this growth, we propose one of the simplest possible models which is consistent with the major observed features of the growth process. In particular, we assume that the fullerene is immersed in a carbon vapor environment, and that the growth occurs as a consequence of the diffusion of the carbon vapor into the fullerene. Moreover, we assume that the classical diffusion equation applies in the …

Optimal Exercise Price Of American Options Near Expiry, W.-T. Chen, Song-Ping Zhu

Faculty of Informatics - Papers (Archive)

This paper investigates American puts on a dividend-paying underlying whose volatility is a function of both time and underlying asset price. The asymptotic behaviour of the critical price near expiry is deduced by means of singular perturbation methods. It turns out that if the underlying dividend is greater than the risk-free interest rate, the behaviour of the critical price is parabolic, otherwise an extra logarithmic factor appears, which is similar to the constant volatility case. The results of this paper complement numerical approaches used to calculate the option values and the optimal exercise price at times that are not close …

Relative Survival After Hospitalisation For Hip Fracture In Older People In New South Wales, Australia, Diane Hindmarsh, Andrew Hayen, Caroline Finch, Jacqueline Ct Close

Faculty of Informatics - Papers (Archive)

Survival after hospitalisation for hip fracture by age group and sex relative to survival in the general population was assessed in people aged 65+. Men had double the risk of death compared with women to 1 year, but age effects lasted only to 3 months. Clinical outcomes need to be improved.We assessed the relative survival of hospitalised fall-related hip fracture patients aged 65+ years leaving hospital in New South Wales, Australia, between July 2000 and December 2003.We carried out a population-based study of all hospital separations for NSW residents with a principal diagnosis of hip fracture (ICD-10-AM S72.0 to S72.2) …

Polyhedral Model For Boron Nitride Nanotubes, Barry Cox, James M. Hill

Faculty of Informatics - Papers (Archive)

The conventional rolled‐up model for nanotubes does not apply to very small radii tubes, for which curvature effects become significant. An existing geometric model for carbon nanotubes proposed by the authors, which accommodates this deficiency and which is based on the exact polyhedral cylindrical structure, is extended to a nanotube structure involving two species of atoms in equal proportion, and in particular boron nitride nanotubes. This generalisation allows the principle features to be included as the fundamental assumptions of the model, such as equal bond length but distinct bond angles and radii between the two species. The polyhedral model is …

Sampling For Subpopulations In Household Surveys With Application To Maori And Pacific Sampling, Robert Graham Clark, Michael Doherty, Angela Forbes, Robert Templeton

Faculty of Informatics - Papers (Archive)

Many NZ national household surveys have a requirement to produce statistics with adequate precision both for the whole of NZ and for important subpopulations, particularly the Maori and Pacific populations. General population surveys which make no special provision for these groups would generally not achieve sufficient precision for Maori and Pacific estimates when these are of particular interest. Kalton and Anderson (1986) described a range of strategies for sampling subpopulations, where the aim is only to produce statistics about the subpopulation and not national statistics. The purpose of this Official Statistics Research fund project is to extend the methods of …

A Conceptlink Graph For Text Structure Mining, Rowena Chau, Ah Chung Tsoi, Markus Hagenbuchner, Vincent Lee

Faculty of Informatics - Papers (Archive)

Most text mining methods are based on representing documents using a vector space model, commonly known as a bag of word model, where each document is modeled as a linear vector representing the occurrence of independent words in the text corpus. It is well known that using this vector-based representation, important information, such as semantic relationship among concepts, is lost. This paper proposes a novel text representation model called ConceptLink graph. The ConceptLink graph does not only represent the content of the document, but also captures some of its underlying semantic structure in terms of the relationships among concepts. The …

The Graph Neural Network Model, Franco Scarselli, Marco Gori, Ah Chung Tsoi, Markus Hagenbuchner, Gabriele Monfardini

Faculty of Informatics - Papers (Archive)

Many underlying relationships among data in several areas of science and engineering, e.g., computer vision, molecular chemistry, molecular biology, pattern recognition, and data mining, can be represented in terms of graphs. In this paper, we propose a new neural network model, called graph neural network (GNN) model, that extends existing neural network methods for processing the data represented in graph domains. This GNN model, which can directly process most of the practically useful types of graphs, e.g., acyclic, cyclic, directed, and undirected, implements a function tau(G,n) isin IR^m that maps a graph G and one of its nodes n …

A Hospital Based Dynamic Platform Workflow Management, Nantika Prinyapol, Joshua P. Fan, S. Lau

Faculty of Informatics - Papers (Archive)

In this paper, we propose the use of dynamic compilation of web services to support workflow management in a hospital setting. Web services related to work practices belong to an organization that have been designed, built and stored in a web services repository. These web services can be shared with multiple functional units within the organization via the intranet or the Internet. The workflow of a health scenario will be presented. Work practice services that were selected will be compiled logically and optimally using the proposed dynamic compilation platform. The final outcome is presented as a web application. The web …

Construction Of Amicable Orthogonal Designs Of Quaternions, Ying Zhao, Jennifer Seberry, Tianbing Xia, Beata J. Wysocki, Tadeusz A. Wysocki

Faculty of Informatics - Papers (Archive)

This paper introduces some construction methods for amicable orthogonal designs over the real and quaternion domains which have been explored for code design before. The proposed construction methods generate a large number of amicable orthogonal designs of quaternions can be used to construct restricted quaternion orthogonal designs which can be applied to orthogonal space-time polarization block codes for wireless communications.

Customizable Data Exchange Based On Web Service, Jun Xu, Gang Xiao, Jiawei Lu, Qianhui Liang, Jun Shen

Faculty of Informatics - Papers (Archive)

In this paper, we propose a method of customizable data exchange based on the service-oriented application environment. We highlight the data exchange model of this method, analyze the components and specific functions of the exchange platform and data exchange node in the model, and finally expound the operation principle and specific implementation of customizable data exchange. We demonstrate this is an efficient way to overcome the shortcomings of the original, single and fixed data exchange mode.

Distance Geometry In Quasihypermetric Spaces. I, Peter Nickolas, Reinhard Wolf

Faculty of Informatics - Papers (Archive)

Let (X,d) be a compact metric space and let (X) denote the space of all finite signed Borel measures on X. Define I:(X)→ by ...

and set M(X)=sup I(μ), where μ ranges over the collection of signed measures in (X) of total mass 1.

The metric space (X,d) is quasihypermetric if for all n, all α₁,…,α_n satisfying ∑ _i=1ⁿα_i=0 and all x₁,…,x_nX, …

Coverings Of Skew Products And Crossed Products By Coactions, David A. Pask, John Quigg, Aidan Sims

Faculty of Informatics - Papers (Archive)

Consider a projective limit G of finite groups G_n. Fix a compatible family δⁿ of coactions of the G_n on a C^*-algebra A. From this data we obtain a coaction δ of G on A. We show that the coaction crossed product of A by δ is isomorphic to a direct limit of the coaction crossed products of A by the δⁿ. If A=C^*(Λ) for some k-graph Λ, and if the coactions δⁿ correspond to skew-products of Λ, then we can say more. We …

Pairwise: A Time Hopping Medium Access Control Protocol For Wireless Sensor Networks, Kwan-Wu Chin

Faculty of Informatics - Papers (Archive)

The availability of low cost, multifunctional embedded devices have become ubiquitous due to their wide ranging application that includes monitoring Radio Frequency Identification (RFID) tagged objects to ambient conditions such as temperature and humidity. Also, these devices can be equipped with a camera and then deployed in hostile environments. A key characteristic of these devices is that they can communicate wirelessly and form an ad-hoc, Wireless Sensor Network (WSN). Devices in a WSN then collaboratively monitor environment factors or objects, and forward data back to one or more central nodes. A key challenge in WSN is ensuring nodes operate in …

Noncommutative Manifolds From Graph And K-Graph C*-Algebras, David A. Pask, Adam Rennie, Aidan Sims

Faculty of Informatics - Papers (Archive)

In [PRen] we constructed smooth (1,∞)-summable semfinite spectral triples for graph algebras with a faithful trace, and in [PRS] we constructed (k,∞)-summable semifinite spectral triples for k-graph algebras. In this paper we identify classes of graphs and k-graphs which satisfy a version of Connes’ conditions for noncommutative manifolds.

Faml: A Generic Metamodel For Mas Development, Ghassan Beydoun, Graham Low, Brian Henderson-Sellers, Haralambos Mouratidis, Jorge J. Gomez-Sanz, Juan Pavon, Cesar Gonzalez-Perez

Faculty of Informatics - Papers (Archive)

In some areas of software engineering research, there are several metamodels claiming to capture the main issues. Though it is profitable to have variety at the beginning of a research field, after some time, the diversity of metamodels becomes an obstacle, for instance to the sharing of results between research groups. To reach consensus and unification of existing metamodels, metamodel-driven software language engineering can be applied. This paper illustrates an application of software language engineering in the agent-oriented software engineering research domain. Here, we introduce a relatively generic agent-oriented metamodel whose suitability for supporting modeling language development is demonstrated by …

Semantic-Aware Delivery Of Multimedia, Joseph Thomas-Kerr, Christian Ritz, Ian Burnett

Faculty of Informatics - Papers (Archive)

This paper describes a system that is able to take arbitrary semantic metadata, and utilize it in the multimedia delivery decision-making process. Format independence is achieved using schema languages to describe the details of any given content or metadata, so that declarative mapping rules can be specified for translating from format-specific data points to format-independent concepts that are directly used by the framework. The system utilizes the criterion of "semantic-distortion", as an extension of Rate-Distortion Optimization based multimedia delivery. Several short video clips were encoded using H.264/SVC scalable video coding, and Scalable-To-Lossless (SLS) audio coding and adapted to four target …

3d Spatial Interaction With The Wii Remote For Head-Mounted Display Virtual Reality, Yang-Wai Chow

Faculty of Informatics - Papers (Archive)

This research investigates the design of a low-cost 3D spatial interaction approach using the Wii Remote for immersive Head-Mounted Display (HMD) virtual reality. Current virtual reality applications that incorporate the Wii Remote are either desktop virtual reality applications or systems that use large screen displays. However, the requirements for an HMD virtual reality system differ from such systems. This is mainly because in HMD virtual reality, the display screen does not remain at a fixed location. The user views the virtual environment through display screens that are in front of the user’s eyes and when the user moves his/her head, …

Ontology-Based Collaborative Inter-Organizational Knowledge Management Network, Nelson K. Y. Leung, Seung Hwan Kang, S. Lau, Joshua P. Fan

Faculty of Informatics - Papers (Archive)

Knowledge management encourages organizations to create and use knowledge continuously to gain competitive advantage. Some knowledge management approaches are industry specific, theoretical and procedure-wise without consideration of system interoperation. The lack of interoperability means heterogeneous systems from different organizations are unable to communicate, cooperate, exchange, and reuse knowledge with one another. Thus a collaborative interorganizational network is necessary. In this paper, we propose the use of ontology for organizations to access and retrieve inter-organizational knowledge in a similar domain. The incorporation of ontology and its mediation methods in the network allows organizations to reuse the interorganizational knowledge to support individual …

Analysis Of An Immobilised Enzyme Reactor With Catalysts Activation, Mark Nelson, Harvinder Sidhu, Soji Adesina

Faculty of Informatics - Papers (Archive)

We investigate the behavior of a reaction described by Michaelis-Menten kinetics in an immobilized enzyme reactor (IER). The IER is treated as a well stirred flow reactor, in which the immobilized bounded and unbounded enzyme species are constrained to remain within the reaction vessel. The product species leaves the IER in the reactor outflow. Before the substrate can react with the enzyme, the enzyme must first be activated by absorption of an activator. We use steady state analysis to identify the best operating conditions or the reactor. To this end, we show that the concentration of product is maximized at …

An Efficient Task Allocation Protocol For P2p Multi-Agent Systems, Dayong Ye, Quan Bai, Minjie Zhang, Khin Than Win, Zhiqi Shen

Faculty of Informatics - Papers (Archive)

Recently, task allocation in multi-agent systems has been investigated by many researchers. Some researchers suggested to have a central controller which has a global view about the environment to allocate tasks. Although centralized control brings convenience during task allocation processes, it also has some obvious weaknesses. Firstly, a central controller plays an important role in a multi-agent system, but task allocation procedures will break down if the central controller of a system cannot work properly. Secondly, centralized multi-agent architecture is not suitable for distributed working environments. In order to overcome some limitations caused by centralized control, some researchers proposed distributed …

Discovery Of Core-Nodes In Event-Based Social Networks, Shaojie Yuan, Quan Bai, Minjie Zhang, Khin Than Win

Faculty of Informatics - Papers (Archive)

Most previous actor-node ranking algorithms for event-based social networks only consider how many events an actor participates in. However in event-based social networks, we should also consider the influence of events when we rank actor-nodes. In this paper we formally define event-based social networks and related concepts, then we propose rules to construct an event-based social network. Algorithms are presented to discover the activity and importance of each actor-node. We test the algorithms by analysing the DBLP data set. In the experiment actors in DBLP data set are ranked based on their activity, importance, and combination of activity and importance, …

Identity-Based Universal Designated Verifier Signature Proof System, Xiaofeng Chen, Guomin Chen, Fangguo Zhang, Baodian Wei, Yi Mu

Faculty of Informatics - Papers (Archive)

The notion of Universal Designated Verifier Signature (UDVS), introduced by Steinfeld et al. in Asiacrypt 2003, allows any holder of a signature to convince any designated verifier that the signer indeed generated the signature without revealing the signature itself, while the verifier cannot transfer the proof to convince anyone else of this fact. Such signature schemes can protect the privacy of signature holders and have applications in certification systems. Very recently, as pointed out by Baek et al. in Asiacrypt 2005, one significant inconvenience of all existing UDVS schemes is that they require the designated verifier to create a public …